My 1998 4.2 L V6 Xlt (Automatic) has 134,1xx miles on it. I got it June of 09 at an auction for 3 grand. Since then, I've invested a little chunk of change in it.
So here's my problem:
At idle in drive/reverse it sits at about 700 to 750 rpm. However, sometimes the tach fluctuates about 100 - 200 rpms. It's enough to where, you can hear it though the flowmasters and at a stop if im not holding the brake it will roll forward when it reves. It's like I'm punching the throttle every second or so (but I'm not). The truck tends to die when I lightly push the gas to accelerate. In neutral if I slowly give it gas it just bogs down and fluctuates. The oil guage goes up and down as well.. the oil light comes on when it gets at very low rpms.. and the truck shakes like it's having a seizure and then dies quite often also. To me, this is a serious problem. I've had it in the shop more than I've driven it since December between intake gaskets, lifters, brakes, tb cleaned, iac, and some other things I can't even remember dumping money into just keeping this thing running. I've put over 15 k miles on it since last June.. about 2.5 months of that time it was in the shop. So I need help. Is it a sensor? I don't think it'd actually be a M.a.f. Then again, I know nothing about engines. I just keep it waxed and park it at the shop nearly every week. Matter of fact, it's been in the shop over just the above problem alone over 3 times in 2 weeks.. Oh, and by the way.. the Check Engine Light stays on.. since my converter was cut off before I purchased it. The mechanic said that's why it stays on. However, before these problems.. it'd stay off for a few days but most of the time it was on. I have no idea what codes it's throwing.. either way.. monday it will be going back to the shop again.
This is what all has been done to my truck since getting it:
Complete inspection of everything
New brakes, rotors turned.. pads.. calipers.. etc.
New set of lifters
New intake gaskets
throttle body cleaned
tune up (the usual stuff along with brakes, oil changes, etc)
New Iac (twice, the first one was disfunctional)
and I've had a few other odds and ends done as well however the paper work isn't infront of me.
So I try to keep this thing properly maintained and looking as good as possible. I got it through an auction for 3 grand. I'd say after speakers, head unit, tires, maintenance, and that really cool steering wheel cover that feels like a temperpedic mattress.... I've spend a grand total of about 5700 on the truck all together (buying it, taxes, plates included.. excluding gas, oil, air freshener trees and tire dressing haha). The truck ran awesome until December.. I had the lifters ticking at start up.. after that is just stays in the shop getting surgery. I really need this fixed because it's hard to pick up girls on your sister's pink 10 speed.
Thanks for any and all comments.

 

We gotta have the codes, and you need to get a converter back on it.

 

What exactly is the converters purpose? smog possibly and what else? I'm sure it serves a purpose since it was there out of the factory.

 

Emissions, and without it you will never be able to clear that P0420 code you are probably getting. It's technically illegal to run without it.

 

Possibly.. however. There is no inspection here. I realize I'm throwing some form of code due to not having a converter. However.. the tach fluctuation, stumbling/dying is my main concern right now..

 

unless backpressure is the case.. who needs a converter if there's no inspection.. sure if you have to dodge tree huggers in CA I can totally understand.. but im in the middle of nowhere. Either way.. it was a disconnected iat cable come to find out.